2 Chemical reactions take place inside cells.2.1Chemical reactions take place inside cells.All cells are made of the same elements. Cells contain four types of large molecules—chemical reactioncarbohydrates,carbohydratelipidproteinnucleic acidcarbohydratesSECTIONOUTLINE

3 Chemical reactions take place inside cells.2.1Chemical reactions take place inside cells.All cells are made of the same elements. Cells contain four types of large molecules—chemical reactioncarbohydrates,carbohydratelipidslipidproteinnucleic acidlipidsSECTIONOUTLINE

4 Chemical reactions take place inside cells.2.1Chemical reactions take place inside cells.All cells are made of the same elements. Cells contain four types of large molecules—chemical reactioncarbohydrates,carbohydratelipids, proteinslipidproteinnucleic acidproteinsSECTIONOUTLINE

5 Chemical reactions take place inside cells.2.1Chemical reactions take place inside cells.All cells are made of the same elements. Cells contain four types of large molecules—chemical reactioncarbohydrates,carbohydrate, and nucleic acids—that support cell function.lipids, proteinslipidAbout two thirds of every cell is water. The propertiesof water are important to cell function.proteinnucleic acidnucleic acidsSECTIONOUTLINE

6 2.1 chemical reaction Chemical reactions take place inside cells.carbohydratelipidThe process by which chemical changes occur. In a chemical reaction, atoms are rearranged, and chemical bonds are broken and formed.proteinnucleic acidKEY CONCEPTSUMMARY

7 2.1 carbohydrate Chemical reactions take place inside cells.lipidA type of carbon-based molecule in living things. Carbohydrates include sugars and starches used for energy or as structural materials. Carbohydrate molecules contain carbon, hydrogen, and oxygen atoms.proteinnucleic acidKEY CONCEPTSUMMARY

8 2.1 lipid Chemical reactions take place inside cells.carbohydratelipidA type of carbon-based molecule in living things. Lipids include fats, oils, and waxes used for energy or as structural materials. Lipids are made up of subunits of fatty acids.proteinnucleic acidKEY CONCEPTSUMMARY

9 2.1 protein Chemical reactions take place inside cells.carbohydratelipidA macromolecule in living things that is made up of smaller molecules called amino acids. Proteins control the chemical activity of a cell and support growth and repair.proteinnucleic acidKEY CONCEPTSUMMARY

10 2.1 nucleic acid Chemical reactions take place inside cells.carbohydratelipidOne of several carbon-based molecules that carry an organism’s genetic code. One of the nucleic acids (DNA) contains the information needed to construct proteins. RNA, a second type of nucleic acid, translates the information into proteins.proteinnucleic acidKEY CONCEPTSUMMARY

12 2.2 chemical energy Cells capture and release energy.glucoseEnergy that is stored in the chemical composition of matter. The amount of chemical energy in a substance depends on the types and arrangement of its atoms. When wood or gasoline burns, chemical energy produces heat. The energy used by the cells in your body comes from chemical energy in the foods you eat.photosynthesischlorophyllcellular respirationfermentationKEY CONCEPTSUMMARY

13 2.2 glucose Cells capture and release energy.chemical energyglucoseglucoseA sugar molecule that is a major energy source for most cells, produced by the process of photosynthesis.photosynthesischlorophyllcellular respirationfermentationKEY CONCEPTSUMMARY

14 2.2 photosynthesis Cells capture and release energy.chemical energyphotosynthesisglucoseThe process by which green plants and other producers use simple compounds and energy from light to make sugar, an energy-rich compound. This is an endothermic process in which light is absorbed and used to change carbon dioxide and water into glucose and oxygen.photosynthesischlorophyllcellular respirationfermentationKEY CONCEPTSUMMARY

15 2.2 chlorophyll Cells capture and release energy.chemical energychlorophyllglucoseA light-absorbing chemical, a pigment, that traps the energy in sunlight and converts it to chemical energy. Found in chloroplasts of plant cells and the cells of other photosynthetic organisms.photosynthesischlorophyllcellular respirationfermentationKEY CONCEPTSUMMARY

18 Materials move across the cell’s membranes.2.3Materials move across the cell’s membranes.Passive transport is the movement of materials from an area of higher concentration to an area of lower concentration. Diffusion and osmosis are examples of passive transport.diffusionpassive transportosmosisactive transportEqual amounts of oxygen move into and out of the cell.SECTIONOUTLINE

19 Materials move across the cell’s membranes.2.3Materials move across the cell’s membranes.Passive transport is the movement of materials from an area of higher concentration to an area of lower concentration. Diffusion and osmosis are examples of passive transport.diffusionpassive transportActive transport is the movement of materials from an areaof lower concentration to an area of higher concentration. Cells need energy to perform active transport.osmosisactive transportenergysaltinside cellSECTIONOUTLINE

20 2.3 diffusion Materials move across the cell’s membranes.passive transportThe tendency of a substance to move from an area of higher concentration to an area of lower concentration.osmosisactive transportKEY CONCEPTSUMMARY

21 2.3 passive transport Materials move across the cell’s membranes.diffusionpassive transportpassive transportThe movement of materials through a membrane without any input of energy.osmosisactive transportKEY CONCEPTSUMMARY

22 2.3 osmosis Materials move across the cell’s membranes.diffusionosmosispassive transportThe movement of water through a membrane from an area of higher concentration to an area of lower concentration.osmosisactive transportKEY CONCEPTSUMMARY

24 2.1 Chemical reactions take place inside cells.I. Chemical reactions take place inside cells.chemical reactionA. All cells are made of the same elements.carbohydrateB. Large molecules support cell function.lipid1. Carbohydratesprotein2. Lipidsnucleic acid3. Proteins4. Nucleic AcidsC. About two thirds of every cell is water.KEY CONCEPTSUMMARY